I know it will be encrypted, but if it is done bit by bit, can you restore the image and use the same keyfiles and passwords after? Can clonezilla do this, or is it a case of once encrypted there is no way back?

I like to image my systems just in case, saves having to do a full re-install should i mess something up_________________I know 43 ways to kill with a SKITTLE, so taste my rainbow bitch.

If you create a bit-exact copy, then yes, you can restore that copy and use it just like it was the original. You may find it more convenient to create encrypted backups of the contained filesystems than to take a full image of the encrypted block device. This reveals to the attacker approximately how much space the plaintext uses, but most threat models consider this an acceptable tradeoff.